Albabstieg Tunnel: Start of Construction early 2014
Stuttgart’s dead-end station is to be transformed into a through station and then link up towards the south with the 50 km long new Wendlingen-Ulm route involving four 4.8 to 8.8 km long tunnels (including the Albvorland Tunnel, Boßler Tunnel and Steinbühl Tunnel totalling 27.3 km in length). The scheme also includes the 5.9 km long Albabstieg Tunnel, which leads from the Alb plateau to the tracks at the Main Station. It overcomes a drop of 95 m with up to 70 m overburden and will be formed by two single-track bores with a shotcreted arched cross-section, which will be linked every 500 m by cross-passages. Light and heavy mass-spring systems will be installed in sections of the tunnel as vibration protection measures.
Both bores will be driven on the dip from the north portal in Dornstadt and from an intermediate point of attack rising towards the north and dipping towards Ulm in the south: the rock consists of layers of White Jura and lower sweet water molasse. The Albabstieg Tunnel will be produced by a JV under the direction of Ed. Züblin AG, Stuttgart. The contract is worth 250 million euros. Driving operations are scheduled to begin in early 2014 with some four and a half years needed to complete the tunnel. Construction work for the new Wendlingen-Ulm route has largely been commissioned and it is due to be opened in 2020. ⇥G.B.